Numerical and Experimental Investigation of Electrical Efficiency Improvement of a Micro Combined Heat and Power (m-CHP) System by Modifying Cam Curve of OHVG Engine

2020 ◽  
Vol 13 (3) ◽  
pp. 203-222
Author(s):  
Fatemeh Goodarzvand-Chegini ◽  
Mohammdreza Habibi ◽  
Saeed Rakhsha ◽  
Leila Samiee ◽  
Meisam Amini ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Engine Speed ◽  
Electrical Power ◽  
Combined Heat And Power ◽  
Hot Water ◽  
Valve Timing ◽  
Engine Torque ◽  
Electrical Efficiency ◽  
Full Load ◽  
Chp System

Background: The purpose of this research is to study the solutions for improving the efficiency of a micro combined heat and power (m-CHP) system based on OHVG (OverHead Valve Gas fueled) engine. Method: In this regard, the effects of valve timing and changing the camshaft on the power and fuel consumption of the engine have been numerically and experimentally investigated. The tests have been performed for engine speed range from 1000 rpm to 3500 rpm, while the engine's fuel was natural gas. The numerical results are found to be in good agreement with experimental ones. The effect of changing the valve timing and camshaft on the performance of the m-CHP has been investigated through the experiments in the test room. The engine speed was 1500 rpm; output hot water was fixed at 55oC; and output electrical power varies from 8 kW to 13 kW in the experiments. Results & Conclusion: The experimental results of the engine test indicate that, by changing the camshaft for full load operation and speed 1500 rpm, engine torque and volumetric efficiency improved by 7.2% and 6.0%, respectively, and fuel consumption decreased by 0.8%. According to the results, the best point for the performance of m-CHP is close to the full load of the electrical power because by increasing the electrical load, electrical efficiency increases from about 25.9% to 32.3%, while the thermal efficiency decreases from about 61.9% to 56.1%.

Independent Evaluation of Measured Performance Data for Cutting-Edge Combined Heat and Power Fuel Cell Systems Installed in Buildings

2012 ◽  
Author(s):  
Heather E. Dillon ◽  
Whitney G. Colella
Keyword(s):  
Electric Power ◽  
Power Output ◽  
Electrical Power ◽  
Combined Heat And Power ◽  
Hot Water ◽  
Electric Power Output ◽  
System Availability ◽  
Cell Systems ◽  
Electrical Efficiency ◽  
System Time

Pacific Northwest National Laboratory (PNNL) is working with industry to independently monitor up to fifteen distinct 5 kilowatt-electric (kWe) combined heat and power (CHP) high temperature (HT) proton exchange membrane (PEM) fuel cell systems (FCSs) installed in light commercial buildings. This research paper discusses an evaluation of the first six months of measured performance data acquired at a one-second sampling rate from real-time monitoring equipment attached to the FCSs at building sites. Engineering performance parameters are independently evaluated. Based on an analysis of the first few months of measured operating data, FCS performance is consistent with manufacturer-stated performance. Initial data indicate that the FCSs have relatively stable performance and a long term average production of about 4.57 kWe of power. This value is consistent with, but slightly below, the manufacturer’s stated rated electric power output of 5 kWe. The measured system net electric efficiency has averaged 33.7%, based on the higher heating value (HHV) of natural gas fuel. This value, also, is consistent with, but slightly below, the manufacturer’s stated rated electric efficiency of 36%. The FCSs provide low-grade hot water to the building at a measured average temperature of about 48.4°C, lower than the manufacturer’s stated maximum hot water delivery temperature of 65°C. The uptime of the systems is also evaluated. System availability can be defined as the quotient of total operating time compared to time since commissioning. The average values for system availability vary between 96.1 and 97.3%, depending on the FCS evaluated in the field. Performance at Rated Value for electrical efficiency (PRVeff) can be defined as the quotient of the system time operating at or above the rated electric efficiency and the time since commissioning. The PRVeff varies between 5.6% and 31.6%, depending on the FCS field unit evaluated. Performance at Rated Value for electrical power (PRVp) can be defined as the quotient of the system time operating at or above the rated electric power and the time since commissioning. PRVp varies between 6.5% and 16.2%. Performance at Rated Value for electrical efficiency and power (PRVt) can be defined as the quotient of the system time operating at or above both the rated electric efficiency and the electric power output compared to the time since commissioning. PRVt varies between 0.2% and 1.4%. Optimization to determine the manufacturer rating required to achieve PRVt greater than 80% has been performed based on the collected data. For example, for FCS unit 130 to achieve a PRVt of 95%, it would have to be down-rated to an electrical power output of 3.2 kWe and an electrical efficiency of 29%.The use of PRV as an assessment metric for FCSs has been developed and reported for the first time in this paper. For FCS Unit 130, a 20% decline in electric power output was observed from approximately 5 kWe to 4 kWe over a 1,500 hour period between Dec. 14th 2011 and Feb. 14th 2012.

Real-Time Measured Performance of Micro Combined Heat and Power Fuel Cell Systems Independently Evaluated in the Field

2012 ◽  
Author(s):  
Heather E. Dillon ◽  
Whitney G. Colella
Keyword(s):  
Electric Power ◽  
Power Output ◽  
Electrical Power ◽  
Combined Heat And Power ◽  
Hot Water ◽  
Electric Power Output ◽  
System Availability ◽  
Cell Systems ◽  
Electrical Efficiency ◽  
System Time

Pacific Northwest National Laboratory (PNNL) is working with industry to independently monitor up to fifteen distinct 5 kilowatt-electric (kWe) combined heat and power (CHP) high temperature (HT) proton exchange membrane (PEM) fuel cell systems (FCSs) installed in light commercial buildings. This research paper discusses an evaluation of the first six months of measured performance data acquired at a one-second sampling rate from real-time monitoring equipment attached to the FCSs at building sites. Engineering performance parameters are independently evaluated. Based on an analysis of the first few months of measured operating data, FCS performance is consistent with manufacturer-stated performance. Initial data indicate that the FCSs have relatively stable performance and a long term average production of about 4.57 kWe of power. This value is consistent with, but slightly below, the manufacturer’s stated rated electric power output of 5 kWe. The measured system net electric efficiency has averaged 33.7%, based on the higher heating value (HHV) of natural gas fuel. This value, also, is consistent with, but slightly below, the manufacturer’s stated rated electric efficiency of 36%. The FCSs provide low-grade hot water to the building at a measured average temperature of about 48.4°C, lower than the manufacturer’s stated maximum hot water delivery temperature of 65°C. The uptime of the systems is also evaluated. System availability can be defined as the quotient of total operating time compared to time since commissioning. The average values for system availability vary between 96.1 and 97.3%, depending on the FCS evaluated in the field. Performance at Rated Value for electrical efficiency (PRVeff) can be defined as the quotient of the system time operating at or above the rated electric efficiency and the time since commissioning. The PRVeff varies between 5.6% and 31.6%, depending on the FCS field unit evaluated. Performance at Rated Value for electrical power (PRVp) can be defined as the quotient of the system time operating at or above the rated electric power and the time since commissioning. PRVp varies between 6.5% and 16.2%. Performance at Rated Value for electrical efficiency and power (PRVt) can be defined as the quotient of the system time operating at or above both the rated electric efficiency and the electric power output compared to the time since commissioning. PRVt varies between 0.2% and 1.4%. Optimization to determine the manufacturer rating required to achieve PRVt greater than 80% has been performed based on the collected data. For example, for FCS unit 130 to achieve a PRVt of 95%, it would have to be down-rated to an electrical power output of 3.2 kWe and an electrical efficiency of 29%.The use of PRV as an assessment metric for FCSs has been developed and reported for the first time in this paper. For FCS Unit 130, a 20% decline in electric power output was observed from approximately 5 kWe to 4 kWe over a 1,500 hour period between Dec. 14th 2011 and Feb. 14th 2012.

scholarly journals Design of a Hybrid Photovoltaic Thermal System in Lebanon

2018 ◽  
Vol 171 ◽  
pp. 02002
Author(s):  
Elie Karam ◽  
Patrick Moukarzel ◽  
Maya Chamoun ◽  
Charbel Habchi ◽  
Charbel Bou-Mosleh
Keyword(s):  
Power Output ◽  
Electrical Power ◽  
Hot Water ◽  
Thermal System ◽  
Conduction Model ◽  
Electrical Efficiency ◽  
Pv Module ◽  
Temperature Loss ◽  
Photovoltaic Thermal System ◽  
Electrical Power Output

Due to global warming and the high toxic gas emissions of traditional power generation methods, renewable energy has become a very active topic in many applications. This study focuses on one versatile type of solar energy: Hybrid Photovoltaic Thermal System (hybrid PV/T). Hybrid PV/T combines both PV and thermal application and by doing this the efficiency of the system will increase by taking advantage of the temperature loss from PV module. The solar radiation and heat will be harnessed to deliver electricity and hot water simultaneously. In the present study a solar system is designed to recycle the heat and improve the temperature loss from PV module in order to supply both electricity and domestic hot water. The project was tested twice in Zouk Mosbeh - Lebanon; on May 18, 2016, and June 7, 2016. The average electrical efficiency was around 11.5% with an average electrical power output of 174.22 W, while with cooling, the average electrical efficiency reaches 11% with a power output of 200 W. The temperature increases by about 7 degrees Celsius from the inlet. The 1D conduction model is also performed in order to design the hybrid PV/T system.

scholarly journals PENGHEMAT BAHAN BAKAR DENGAN MENGGUNAKAN PIPA KATALIS METODE HYDROCARBON CRACK SYSTEM GANDA PADA SEPEDA MOTOR 4 TAK 160 CC

2019 ◽  
Vol 2 (2) ◽  
pp. 1
Author(s):  
Sena Mahendra ◽  
Fahmy Fatra ◽  
Akhmad Riszal Riszal ◽  
Didik Rohmantoro
Keyword(s):  
Fuel Consumption ◽  
Engine Speed ◽  
Engine Performance ◽  
Fuel Saving ◽  
Pipe Length ◽  
Engine Torque ◽  
Fuel Prices ◽  
Performance Time ◽  
In Series ◽  
High Octane

Motorized vehicles with economical fuel, agile, fast, and practical are some of the main factors consumers determine the choice of buying a motorcycle. People who own motorcycles under 2000 have not been equipped with fuel-saving devices, so they are wasteful of fuel and must be smart to save fuel. Many motorcycle manufacturers release the newest fuel-efficient products, but they affect the engine's performance. The price of premium fuel types is Rp. 6,500.00 per liter, petalite Rp. 7,600.00 per liter, firstly Rp. 8,900.00 per liter, and Pertamax turbo Rp. 10,100.00 per liter. High fuel prices encourage researchers to make various fuel-saving innovations. The purpose of this study is to develop an HCS catalyst pipe design double spiral model arranged in series to save fuel above 67% on a 4 stroke motorcycle without affecting the engine performance. The research method uses independent variables with engine speed, pipe length, pipe diameter, and Pertamax volume. Dependent variable by testing engine torque and power, fuel consumption time, temperature, and noise of the 156.7cc Mega Pro motorcycle. The addition of dual HCS catalyst spiral pipes and Pertamax volumes adds to engine performance time. At a length of 500 mm and 2000 ml, the Pertamax volume for the engine speed of 3500 rpm is only able to save fuel by 52.52%. The most optimal HCS double catalyst spiral pipe design is a 500 cm long pipe with a volume of Pertamax 2000 ml. In addition to engine performance time on the catalyst spiral pipe design can increase engine torque and power by 92.3% at 3500 rpm and reduce the temperature by 12.34% at 6000 rpm, and 1.93% noise at 4000 rpm. Increasing the double HSC catalyst spiral pipe and Pertamax volume can increase the hydrocarbon content of fuel entering the combustion chamber supplied from Pertamax vapor. Premium fuel (C8H18) plus Pertamax vapors. This makes the fuel content has a high octane value, greater engine power, and low fuel consumption. A high octane value affects perfect engine combustion, reduced knocking, low engine temperature, and decreased noise.Kendaraan bermotor dengan bahan bakar yang irit, lincah, cepat, dan praktis merupakan salah satu faktor utama konsumen menentukan pilihan membeli sepeda motor. Masyarakat yang memiliki sepeda motor di bawah tahun 2000 belum dilengkapi dengan alat penghemat bahan bakar, sehingga boros bahan bakar dan harus pintar menghemat bahan bakar. Banyak produsen sepeda motor yang mengeluarkan produk terbarunya paling irit bahan bakar, tetapi mempengaruhi performa mesinnya. Harga bahan bakar jenis premium Rp. 6.500,00 per liter, pertalite Rp. 7.600,00 per liter, pertamax Rp. 8.900,00 per liter, dan pertamax turbo Rp. 10.100,00 per liter. Harga bahan bakar yang tinggi mendorong peneliti melakukan berbagai inovasi penghemat bahan bakar.Tujuan penelitian ini mengembangkan desain pipa katalis HCS model spiral ganda yang disusun seri sehingga mampu menghemat bahan bakar diatas 67% pada sepeda motor 4 tak tanpa mempengaruhi performa mesin. Metode penelitian menggunakan variabel bebas dengan putaran mesin, panjang pipa, diameter pipa, dan volume pertamax. Variabel terikat dengan menguji torsi dan daya mesin, waktu konsumsi bahan bakar, temperatur, dan kebisingan sepeda motor Mega Pro 156,7cc. Penambahan pipa spiral katalis HCS ganda dan volume pertamax menambah waktu performa mesin. Pada panjang 500 mm dan 2000 ml volume pertamax untuk kecepatan putaran mesin 3500  rpm hanya mampu menghemat bahan bakar sebesar  52,52%. Desain pipa spiral katalis HCS ganda  yang paling optimal dari yaitu pipa dengan panjang 500 cm dan volume pertamax 2000 ml. Selain waktu performa mesin pada desain pipa spiral katalis ini dapat meningkatkan torsi dan daya mesin sebesar 92,3% pada putaran 3500 rpm serta mengurangi temperatur 12,34% pada putaran 6000 rpm, dan kebisingan 1,93% pada putaran 4000 rpm. Bertambahnya pipa spiral katalis HSC ganda dan volume pertamax dapat meningkatnya kandungan hidrokarbon bahan bakar yang masuk ke ruang pembakaran disuplay dari uap pertamax. Bahan bakar premium (C8H18) di tambah uap pertamax.menjadikan kandungan bahan bakar memiliki nilai oktan tinggi, daya mesin yang lebih besar dan komsumsi bahan bakar rendah. Nilai oktan tinggi mempengaruhi pembakaran mesin sempurna, knocking berkurang, temperatur mesin rendah, dan kebisingan menurun

Experimental Characterisation of a Humidified T100 Micro Gas Turbine

2016 ◽  
Author(s):  
Marina Montero Carrero ◽  
Ward De Paepe ◽  
Jan Magnusson ◽  
Alessandro Parente ◽  
Svend Bram ◽  
...  
Keyword(s):  
Power Output ◽  
Rotational Speed ◽  
Gas Turbines ◽  
Electrical Power ◽  
Water Injection ◽  
Hot Water ◽  
Electrical Efficiency ◽  
Exhaust Gases ◽  
Heat Demand ◽  
Experimental Characterisation

Despite the potential of micro Gas Turbines (mGTs) for Combined Heat and Power (CHP), this technology still poses limitations that curb its widespread adoption, especially for applications with a variable heat demand. In fact, whenever the user heat demand is low, mGTs are generally shut down. Otherwise, the high temperature exhaust gases have to be blown off and the resulting electrical efficiency is not high enough to sustain a profitable operation. If, instead of released, the heat in the exhaust gases is re-inserted in the cycle — by injecting hot water and transforming the mGT into a micro Humid Air Turbine (mHAT) — the electrical efficiency can be increased during periods of reduced heat demand, thus improving the economics of the technology. Although the enhanced performance of the mHAT cycle has been thoroughly investigated from a numerical point of view, results regarding the experimental behaviour of this technology remain scarce. In this paper, we present the experimental characterisation of the mHAT located at the Vrije Universiteit Brussel (VUB): based on the T100 mGT and equipped with a spray saturation tower. These are the first experimental results of such an engine working at nominal load with water injection. In addition, the control system of the unit has been modified so that it can operate either at constant electrical power output (the default setting) or at constant rotational speed. The latter option allowed to better assess the effect of water injection. Eperimental results demonstrate the patent benefits of water injection on mGT performance: at fixed rotational speed, the power output of the mHAT increases by more than 30%while the fuel consumption rises only by 11%. Overall, the electrical efficiency in wet operation increases by up to 4.2% absolute points. Future work will involve further optimising the current facility to reduce pressure losses in the air and water circuits. In addition, we will carry out transient simulations and experiments in order to further characterise the facility.

scholarly journals Designing, manufacturing and testing of a micro combined heat and power (micro-CHP) system

2017 ◽  
Vol 2 (3) ◽  
pp. 197-201
Author(s):  
Masood Ebrahimi ◽  
Mansour Lahonian ◽  
Sirwan Farhadi
Keyword(s):  
Heat Recovery ◽  
Tap Water ◽  
Combined Heat And Power ◽  
Hot Water ◽  
Domestic Hot Water ◽  
Heating Source ◽  
Waste Energy ◽  
Overall Efficiency ◽  
Chp System ◽  
Main Components

In the present paper a micro-CHP is designed, built and tested based on a 5 kW diesel engine that is chosen to recover its water jacketing and exhaust waste energy and convert it into hot water. The hot water may be used as heating source or domestic hot water. Heat recovery for the lube oil, radiation, convection, and conduction to ambient is not used since they all count for only 13% of the inlet fuel energy. The results include the main characteristics in the design section, some pictures of the main components, the temperature of exhaust, water jacketing and tap water at different points of the system. In addition the heat recovery at different engine loads is also given. The experiments and results show that the overall efficiency of the CHP system can reach 60% which means more than 30% increase of efficiency when comparing with the case when only electricity was supposed to be produced by the engine.

scholarly journals Evaluation of the Energy Performance of an Organic Rankine Cycle-Based Micro Combined Heat and Power System Involving a Hermetic Scroll Expander

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Jean-François Oudkerk ◽  
Sylvain Quoilin ◽  
Sébastien Declaye ◽  
Ludovic Guillaume ◽  
Eric Winandy ◽  
...  
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Heat And Power ◽  
Hot Water ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Electrical Efficiency ◽  
Scroll Expander ◽  
Significant Difference ◽  
Temperature Application

This paper evaluates the performance of an organic Rankine cycle (ORC) based micro- combined heat and power (CHP) unit using a scroll expander. The considered system consists of a fuel boiler coupled with an ORC engine. As a preliminary step, the results of an experimental campaign and the modeling of a hermetic, lubricated scroll compressor used as an expander are presented. Then, a fluid comparison based on several criteria is conducted, leading to the selection of R245fa as working fluid for the ORC. A simulation model is then built to evaluate the performance of the system. The model associates an ORC model and a boiler model, both experimentally validated. This model is used to optimize and size the system. The optimization is performed considering two degrees of freedom: the evaporating temperature and the heat transfer fluid (HTF) mass flow rate. Seasonal simulation is finally performed with a bin method according to the standard PrEN14825 for an average European climate and for four heat emitter heating curves. Simulation results show that the electrical efficiency of the system varies from 6.35% for hot water at 65 °C (high temperature application) to 8.6% for a hot water temperature of 22 °C (low temperature application). Over one entire year, the system exhibits an overall electrical efficiency of about 8% and an overall thermal efficiency around 87% without significant difference between the four heat emitter heating curves. Finally, some improvements of the scroll expander are evaluated. It is shown that by increasing the maximum inlet temperature (limited to 140 °C due to technical reasons) and using two scroll expanders in series, the overall electrical efficiency reaches 12.5%.

Independent Analysis of Real-Time, Measured Performance Data From Microcogenerative Fuel Cell Systems Installed in Buildings

2015 ◽  
Vol 12 (3) ◽  
Author(s):  
Heather E. Dillon ◽  
Whitney G. Colella
Keyword(s):  
Fuel Cell ◽  
Electric Power ◽  
Power Output ◽  
Electrical Power ◽  
Hot Water ◽  
Electric Power Output ◽  
System Availability ◽  
Cell Systems ◽  
Electrical Efficiency ◽  
System Time

Pacific Northwest National Laboratory (PNNL) is working with industry to independently monitor up to 15 distinct 5 kW-electric (kWe) combined heat and power (CHP) high temperature (HT) proton exchange membrane (PEM) fuel cell systems (FCSs) installed in light commercial buildings. This research paper discusses an evaluation of the first six months of measured performance data acquired at a 1 s sampling rate from real-time monitoring equipment attached to the FCSs at building sites. Engineering performance parameters are independently evaluated. Based on an analysis of the first few months of measured operating data, FCS performance is consistent with manufacturer-stated performance. Initial data indicate that the FCSs have relatively stable performance and a long-term average production of about 4.57 kWe of power. This value is consistent with, but slightly below, the manufacturer's stated rated electric power output of 5 kWe. The measured system net electric efficiency has averaged 33.7%, based on the higher heating value (HHV) of natural gas fuel. This value, also, is consistent with, but slightly below, the manufacturer's stated rated electric efficiency of 36%. The FCSs provide low-grade hot water to the building at a measured average temperature of about 48.4 °C, lower than the manufacturer's stated maximum hot water delivery temperature of 65 °C. The uptime of the systems is also evaluated. System availability can be defined as the quotient of total operating time compared to time since commissioning. The average values for system availability vary between 96.1 and 97.3%, depending on the FCS evaluated in the field. Performance at rated value for electrical efficiency (PRVeff) can be defined as the quotient of the system time operating at or above the rated electric efficiency and the time since commissioning. The PRVeff varies between 5.6% and 31.6%, depending on the FCS field unit evaluated. Performance at rated value for electrical power (PRVp) can be defined as the quotient of the system time operating at or above the rated electric power and the time since commissioning. PRVp varies between 6.5% and 16.2%. Performance at rated value for electrical efficiency and power (PRVt) can be defined as the quotient of the system time operating at or above both the rated electric efficiency and the electric power output compared to the time since commissioning. PRVt varies between 0.2% and 1.4%. Optimization to determine the manufacturer rating required to achieve PRVt greater than 80% has been performed based on the collected data. For example, for FCS Unit 130 to achieve a PRVt of 95%, it would have to be down-rated to an electrical power output of 3.2 kWe and an electrical efficiency of 29%. The use of PRV as an assessment metric for FCSs has been developed and reported for the first time in this paper. For FCS Unit 130, a maximum decline in electric power output of approximately 18% was observed over a 500 h period in Jan. 2012.

Computation of Overdrive Gear Ratio in Vehicle Gearbox With Considering Fuel Economy and Gearbox Specifications

2010 ◽  
Author(s):  
R. Ghafoori Ahangar ◽  
M. R. Meigounpoory ◽  
A. Eskandari
Keyword(s):  
Fuel Consumption ◽  
Fuel Economy ◽  
Engine Speed ◽  
Rotational Velocity ◽  
Gear Ratio ◽  
Effective Parameters ◽  
Engine Operation ◽  
Engine Torque ◽  
Effective Velocity ◽  
Vehicle Engine

In this article, the gear ratio of RD (An Iranian made car by Iran Khodro Co.) vehicle gearbox with considering fuel economy and gearbox specifications is evaluated. In the first step, the gearbox advantages and its effects on the engine rotational velocity with considering road load and engine torque are investigated. It is distinguished that in a specified velocity of vehicle, engine speed in overdrive state is very lower than engine speed in fourth gear. It means that noise and fuel consumption and engine wearing and damages will be decreased. The optimized region of engine operation is identified. Using a geometric progression between automotive gear ratios and entering number of effective parameters such as specific fuel consumption, minimum mean effective velocity, and etc., overdrive gear ratio is computed. Finally the overdrive gear ratio is chosen 0.81 for vehicle.

Modeling and Performance Evaluation of a Large-Scale SOFC-Based Combined Heat and Power System for Biogas Utilization at a Wastewater Treatment Facility

2012 ◽  
Author(s):  
A. A. Trendewicz ◽  
R. J. Braun
Keyword(s):  
Wastewater Treatment ◽  
Performance Evaluation ◽  
Large Scale ◽  
Exergy Analysis ◽  
Combined Heat And Power ◽  
Small Scale ◽  
Treatment Facility ◽  
Electrical Efficiency ◽  
Wastewater Treatment Facility ◽  
Chp System

Biogas has been identified as an attractive fuel for solid oxide fuel cells (SOFCs) due to its high methane content and its renewable status. Current experimental and modeling research efforts in this field have focused mainly on single-cell and small-scale systems performance evaluation. In this paper a large scale biogas source (∼15.5 MW) from a large wastewater treatment facility is considered for integration with an SOFC-based system. Data concerning biogas fuel flow rate and composition have been acquired from a wastewater reclamation facility in Denver and are used as inputs to a steady-state model of an SOFC combined heat and power (CHP) system developed with Aspen Plus. The proposed system concept for this application comprises an advanced SOFC system with anode gas recirculation (AGR) equipped with biogas clean-up and a waste heat recovery system. The system performance is evaluated at near atmospheric pressure with a 725°C nominal operating temperature of the fuel cell stack and system fuel utilization of 80%. The average biogas fuel input has a composition of 60% CH4, 39% CO2, and 1% N2 on a dry molar basis. The SOFC-CHP system employs 80% internal reforming at a steam-to-carbon ratio of 1.2. The system offers a net electrical efficiency of 51.6% LHV and a net CHP efficiency of 87.5% LHV. The influence of the operating parameters on the system efficiency is investigated and discussed. The individual contribution of system components to the total inefficiency of the system is quantified with an exergy analysis. Exergy analysis results indicate that the system could offer a tremendous energy efficiency improvement when compared to biogas-supplied combustion turbines currently installed at the facility which operate with an average net electrical efficiency of 25%-LHV.

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